We start with a definition of some of the terms we use in this document for the sake of being precise and clear. We also define the labels used in this document.
To assert. In digital electronics it means to make a wire on or off, as needed, or a set of wires to be in any combination on and off, as needed. In this context “on” an “off” generally mean one of the two possibilities of a binary representation, as on=5V, off=0V, on=magnetic field up, off=magnetic field down, on=light, off=dark, etc.
B/H/D after a number, or in subindex, stands for binary/hexadecimal (hex)/decimal number representation. For example: 1010B=0AH=10D
Bus. A set of wires grouped according to its function. For example, the address bus is the set of wires which carries the address value for something, the data bus is the set of wires which carries the data, or numerical value for something.
Demultiplexer. A type of electronic switch with a single input and a plurality of outputs, also with a number of binary inputs capable of creating a binary address which can select which of the outputs will be connected to the single input (cf. multiplexer). The device of our invention uses a demultiplexer capable of also latching the output selection, that is, a demultiplexer that maintain the connection between the single input and the selected output even after the address is out from its address port (it latches), or even if the address changes to another value.
Integrated circuit. As used herein, the term “integrated circuit” refers to a small-scale, electronic device densely packaged with more than one integrated, electrical component. The components are manufactured on the surface of semiconductor material. There are various scales of integrated circuits that are classified based on the number of components per surface area of the semiconductor material, including small-scale integration (SSI), medium-scale integration (MSI), large-scale integration (LSI), very large-scale integration (VLSI), ultra large-scale integration (ULSI)
Latch. A term used in digital electronics meaning the capability to keep some particular configuration, or output, or logic, or selection, even after the selecting source, etc., is no longer active, or even if the selecting source is changed to a different value. Another way to look at it is that a latched device has memory to keep a configuration when instructed to do so. A standard wall light switch is an example of a latch because it keeps the last state it was set by a human being, either on or off.
Measuring tip. The very tip of the measuring wire, sometimes referred as electrode in current art, made of metal or some other electrically conducting material. In current art devices the measuring tip is generally at the end of a thin, stiff wire, typically 100 micrometers diameter, separated by 100 micrometers, or more, while in our invention the measuring tip is a metallic area as small as a few micrometers, typically 5 micrometers but can be less or more according to the need, separated by as little as 5 micrometers, at the surface of the device of our invention. Current art is capable of manufacturing measuring tips for our invention that are less than one micrometer in diameter, and the shape is not necessarily circular.
Multiplexer (MUX) a type of electronic switch with a plurality of inputs and one single output, also with a number of binary inputs capable of creating a binary address which can select which of the inputs will be connected to the single output. (cf. Demultiplex).
Neural sensor. As used herein, the term “neural sensor” means an implantable device for sensing neural signals. Examples of neural sensors include microwire electrode arrays, optical sensors, microwires, magnetic field detectors, chemical sensors, and other suitable neural sensors which are known to those of skill in the art upon consideration of the present disclosure.
Picafina. A supporting structure used by the main embodiment of our invention, generally similar to the devices used in Deep Brain Stimulation but potentially with far more tips or electrodes than DBS devices, which is strong enough to allow it to be inserted in the brain or other body structures, and which contains the necessary wires for connecting the measuring tips and the address decoders with the controlling and measuring instruments. For use in human animals, he dimension of a type I picafina is approximately the diameter of a wide drinking straw (5 mm.), its length being the necessary to reach the desired depth in the body. For smaller animals (as a mouse), the picafinas would be accordingly smaller, both in diameter and length, while for larger animals (as a whale or an elephant), the picafinas would be accordingly larger.    h_1=length of the distal part of the picafina, which is devoid of electrical pads.    h_2=length of the middle part of the picafina, which is populated with electrical pads.    h_3=length of the proximal part of the picafina, which is devoid of electrical pads.    13_1=Cross section of the picafina, perpendicular to its major axis (z-axis).    13_2=Area that receives the electrical stimulation.    13_3=Target region, area that needs to receive stimulation.    100=body of picafina of my invention.    110—xx—yy=pads/electrical contacts on the surface of body 100.    810—xx—yy=on/off transistor that connect each electrical pad to the electrical power source, also indicated as 810x, when referring to any of the possible transistors, also indicated as SW or SWx when referring to the transistors as their function of switches.    811—xx—yy=on/off switches for power wires (either fixed voltage or fixed current) that brings power to the stimulating pads 110 on the picafina's surface.    820—xx—yy=timer or pulse stretcher, where xx indicates which “ring” or z-distance, while yy indicates which of the 12 pads in each “ring”. In the main embodiment xx takes any value from 01 to 16, while yy takes any value from 01 to 12.    830—xx—yy=address decoders.    840—xx—yy=address decoders for different voltage options.    200=address lines or address bus for stimulating pads.    201=address lines or address bus for power carrying wires for the stimulating pads.    200prox=proximal side of digital address lines for selection of stimulating pads 110.    201prox=proximal side of digital address line for power carrying wires.    210prox=proximal side of electrical power to power the picafina electronics.    211prox=proximal side of stimulation power carrying wire (one 211 in main embodiment, few 211 in claimed secondary embodiment.    212=ground wire.    latch=latching signal wire.    1200=microcontroller.    1230=current controller.
It is well established that the neuron signals are electrical propagating signals. The roots of this fact can be traced at least to the Italian Luigi Galvani as early as 1771 with his famous frog's leg experiment. Electrically stimulating neurons that carry orders to muscles, or electrically stimulating the muscles directly, can therefore cause the muscles to contract or relax. It follows that the spinal cord and the whole brain, being as they are a collection of neurons, are electrical devices, the function of which could be expected to be affected if electrical currents were forced on them by some external agent.
Focusing attention now on the brain, it has been established that different brain functions occur in different parts of it, though some parts of the brain are known to be shared by more than one function. The French Paul Broca is credited with the first unequivocal evidence that the brain is segmented in areas with specialized functions (brain workers say “area” for what is actually a volume, a particular three dimensional part of the brain, practice that I will follow here, occasionally calling the attention of the reader to this misuse of the word). Paul Broca proved that speech is processed and controlled at a small area (that is, a volume) today known as the “Broca area” which is located in the left frontal lobe. Today the parts of the brain that are associated with speech, or with vision, or with the motion of the hand or with the motion of the big toe on the left foot, an so on, are all known; the brain is all mapped, as known in the trade. Eric R. Kandel (Kandel (2000)) gives a good overview of the current state of the art from the academic point-of-view.
It follows from these two facts that electrical stimulation of any particular area of the brain (that is, a volume) should affect the function that depends on this area: speech, vision, motor, etc. This was indeed experimentally determined to be true, and eventually brain electrical stimulators were developed to affect parts that became dysfunctional. Brain stimulation to correct for motor disorders is the most common clinical application today, but stimulation can also cause emotions when it happens in the area that is associated with them. Similarly, stimulation of nerves that carry information from the body to be brain can stop (or cause) pain, and electrically stimulating the heart can keep it at the correct pace, or even to restart it when it happens to stop, as is done with pacemakers and defribilators. Electrically stimulating neurons that carry orders to muscles, or electrically stimulating the muscles directly, can therefore cause the muscles to contract or relax. This is what is achieved with heart pacemakers and heart defibrillators. A pacemaker could, in principle work stimulating the part of the brain that starts the process (assuming it is not autonomous), but this would be more complicated than stimulating the heart directly, so pacemakers are designed to affect the heart directly, and not the origin of the signal.
Leaving aside the mechanisms that underlie the result of electrical stimulation, which are not well known in all cases, it is possible today to use direct electrical stimulators to modify motor malfunctions as Parkinson's disease, essential tremor or epilepsy, or mood states as depression, or complex syndromes as eating disorders. Said brain electrical stimulation is achieved with electrodes permanently implanted in the desired part of the brain, which are connected to the necessary electrical power source (batteries or the like) and electronic circuitry to generate the appropriate electrical pulse. Severe diseases as Parkinson's disease are now treatable and often totally or largely curable, or at least substantially controlled, with direct electrical stimulation to the appropriate part of the brain. For Parkinson's disease stimulation, the device is one of a class generally known as Deep Brain Stimulators (DBS), because all the known parts of the brain that receive electrical stimulation to counter Parkinson's disease are located deep inside it, as the thalamus, the subthalamic nucleus (STN), the basal ganglia, or internal globus pallidus (GPi) the internal capsule and the nucleus accumbens. The electrical pulse for DBS is AC (alternate current) at f=˜180 Hz (or 5.56 milliseconds between pulses), each pulse lasting approximately 90 microseconds (pulsewidth). The voltage depends on the patient, varying from as low as 2.5 V to as high as 5 V (all values approximate, varying between patients and also with time on the same patient). A separate class of stimulators are the superficial brain stimulators, known as cortical stimulators, that stimulate the brain cortex, which could also use the invention disclosed in this patent application with appropriate adaptations, largely on the geometry of the stimultor. There are also spinal stimulators, that stimulate the nerves at the spinal column, and other parts of the body, generally for pain control, but also for other problems. There are heart stimulators or pacemakers and also heart defribilators. These latter, heart pacemakers and defribilators, differ much from the device disclosed as the main embodiment of this patent application, but the same core principle disclosed in this invention, the method and means of more precisely applying the stimulation, and of shaping the electric field, so as to guide the current, apply to them too. Another application is artificial muscle stimulation, where artificial materials capable of contraction or distention when receiving the appropriate signal are used as artificial muscles. Another class of devices is composed of measuring probes, designed to measure the voltage (or current) in the brain or other body parts. All these variations can incorporate the system and method disclosed here to allow the use of a very large number of electrical contacts for stimulation or for measurement.